Combination plug and switch



Nov. 26, 1935. M. B. SAWYER COMBINATION PLUG AND SWITCH Filed Nov. 4,19515 INVENTOR.

MARION B \SAwYE R ATTORNEY.

Patented Nov. 26, 1935 UNITED STATES PATENT OFFICE 7 Claims.

This invention is a means for conveniently making and breaking the powercircuit for an electric tool or appliance, and is particularlyapplicable to portable electric tools.

It is the object of the invention to provide a switch for the powercircuit for an electric tool, spaced from and supported independently ofthe tool, so that the tool is relieved of the weight of the switch as isparticularly advantageous with portable tools, and the switch is out ofthe Way for minimizing the liability of damaging the same, and is spacedfrom the operator so as to protect him against injury in the event ofarcing at the switch.

It is a further object of the invention to independently support andspace the switch from the tool, but to operate the switch from the toolso that the operator may conveniently control the tool.

It is a still further object of the invention to independently supportand space the switch from the tool, but to adapt the switch fortransportation with the tool from one power outlet to an other, so thatinstead of a separate switch being necessary at each outlet the oneswitch is adapted to control its corresponding tool at all times.

It is a still further object of the invention to readily plug in thetool at any desired power outlet, with its switch supportedindependently of the tool and in spaced relation therefrom so that thetool may be conveniently handled, with both the switch mechanism and theoperator adequately protected.

Further objects of the invention will be readily understood from thefollowing description of the accompanying drawing, in which:

Fig. 1 is a perspective view of a portable tool and its switchmechanism, showing the tool ready to be plugged in at a power outlet.

Fig. 2 is a front perspective view of the switch mechanism.

Fig. 3 is a rear elevation of the switch mechanism, with the housingpartly broken away.

Fig. 4 is a vertical section on the line 44 of Fig. 3.

The switch mechanism may be used in connection with any electric tool orappliance but is particularly applicable to portable electric tools, andis therefore illustrated in connection with a portable electric grinderI having a shaft 2 for a grinding element 3, and provided with a usualhandle 4. A cable 5 is connected to the grinder and is adapted to beplugged in at a power outlet 6, so that when the cable is plugged in thetool is readily portable within the radius defined by the length of itscable, and by disconnecting the cable from the power outlet and movingthe tool to a new position and plugging in the cable at a differentoutlet, the tool is readily transportable and adapted for use wherever apower outlet is 5 available.

The switch for the power circuit for the tool is spaced from the tooland is supported independently thereof, so that when the tool is in useit is relieved of the weight of the switch and both the 10 switchmechanism and the operator are protected; but the switch is adapted fortransportation with the tool from one power outlet to another so thateach tool has is own switch and there is no necessity for a switchmechanism at each of 15 the available power outlets; and when a tool andits switch have been moved to a desired power outlet the cable for thetool is adapted to be readily plugged in, with the switch mechanismcontrolling the tool but spaced from and sup- 20 ported independentlythereof.

For this purpose the free end of the cable 5 has a usual plug 1 adaptedfor quick-detachable engagement with a power outlet 6, and the switchmechanism is connected to the wires of the cable 25 5 and is preferablyadjacent and supported by the plug 1, so that the quick-detachableconnection 6-! mounts the switch adjacent the outlet 6 where it is outof the way and spaced from the tool by the length of the cable, and withthe tool 30 relieved of the weight of the switch. When the plug 1 iswithdrawn from outlet 6 for moving the tool to another outlet, the plugand switch are preferably suspended as a unit from the free end of thecable 5, so that the entire assembly may 36 be readily transported andagain connected to the power circuit by simply plugging in at an otheroutlet.

As an instance of this arrangement, the switch is preferably mounted onone face of a plate or 40 support I 0 with the plug I projecting fromthe opposite face of this plate and the cable 5 extending from the endof the plate. A housing ll may enclose the switch and is preferablydetachably secured to the margin of plate l0, and may 45 cooperate withthe plate for clamping the end of the cable relative to the switchassembly. The switch may be a'usual magnetic relay switch, comprising anelectro-magnet l2 having a normally spring retracted armature l3carrying con- 50 tact strips H which are adapted to bridge spacedcontacts l5|6; and the elements of the switch are preferably mounted ona base H, which is in turn supported on plate Ill, preferably in spacedrelation therefrom as shown at I8. 55

The plug 1 and the outlet 6 may be of usual construction, the plugcomprising contact prongs l9 projecting from a base 20 which is mountedon plate in, and the cooperating outlet having slots 2i adapted fordetachable reception of the contact prongs. The outlet 6 is shownprovided with four slots, three for the lines of the power circuit andthe fourth a ground connection, and the plug 1 has the same number ofprongs connected to corresponding wires 22 of the cable 5. The switch isin circuit between the wires 22 and the prongs [9, the connections beingmade through an opening 23 in the plate which communicates with the openbore of base 20 and with the space l8 beneath the base I1, and theprongs l9 have terminals 24 and the contacts l-IS have terminals 2526for making the necessary connections.

In order to securely clamp the end of cable 5 between the plate i0 andthe housing I I, the end of the plate may form a recess 30 adapted toreceive the cable with the end wall of housing H forming a cooperatingrecess 3| adapted to fit over the cable; and a split collar may beclamped on the cable, with one half of the split collar integral withand projecting from the housing I l as shown at 32, and the other halfof the split collar comprisin a separate element 33 which is adapted fordetachable assembly with the collar element 32 by means of screws 34.

The magnetic relay switch is preferably controlled from the tool so thatthe control is read ily accessible to the operator, and for this purposethe cable 5 in addition to the four wires 22 for the power circuit andthe ground connection, also carries a pair of wires 36 which areconnected to a switch 3'! mounted on the tool. This switch may be a.usual thumb switch mounted on the handle 4; and the opposite ends ofwires 36 are connected to the terminals 38 for the winding of the magnet12, the connections being such that the thumb switch 31 controls theenergizing and tie-energizing of the magnet l2, for making and breakingthe power circuit at the contacts [5-4 6.

The tool is thus readily controlled from the handle of the tool, at apoint convenient to the operator, but the power circuit is made andbroken not at the tool but at the opposite end of the cable, and theswitch for the power circuit is supported not by the tool but by theplugged-in connection B--=', and the magnetic switch is a unitary partof the plug '1, whereby the entire assembly may be readily transportedand plugged in at any usual power outlet.

I claim:

i. In combination, a support, an electric cable, an electric contactplug at one face of the support, a switch at the opposite face of thesupport in electric circuit with the plug and the cable, and a housingmounted on the support and enclosing the switch, the housing and supportcooperating to clamp the cable therebetween.

2. In combination, a support, an electric cable, an electric contactplug carried by the support, a switch carried by the support and inelectric circuit with the plug and the cable, and means for clamping thecable relative to the support.

3. In combination, a support, an electric cable, an electric contactplug at one face of the support, a switch at the opposite face of thesupport in electric circuit with the plug and the cable, a

control circuit for the switch, and an electric 5 switch for the controlcircuit, said switch being re mote from the support.

4. In combination, a portable electric cable adapted for connection atone end to a portable electric tool, an element of an electric contactmeans, which comprises quick-detachable cooperating plug and socketelements, at the opposite end of the cable and portable with the cable,a relay switch portable with the cable and remote from the firstmentioned end of the cable and in electric circuit with the cable andwith said element of the electric contact means which is at the firstmentioned end of the cable, a control circuit for the relay switch, andan electric switch for the control circuit, said switch being remotefrom the relay switch.

5. In combination, a portable electric cable adapted for connection atone end to a portable electric tool, a support at the opposite end ofthe cable and portable with the cable, an element of an electric contactmeans, which comprises quickdetachable cooperating plug and socketelements, mounted on the support, a relay switch mounted on the supportand in electric circuit with the cable and with the element of theelectric contact means which is mounted on the support, a controlcircuit for the relay switch, and an electric switch for the controlcircuit, said switch being remote from the relay switch.

6. In combination, a portable electric cable adapted for connection atone end to a portable electric tool, a support at the opposite end ofthe cable and portable with the cable, a relay switch mounted on thesupport, the cable having electrical connection with one side of therelay switch, 40 means for securing the cable relative to the support,an element of an electric contact means, which comprisesquick-detachable cooperating elements, having electrical connection withthe other side of the relay switch and being portable with the cable, acontrol circuit for the relay switch, and an electric switch for thecontrol circuit, said switch being remote from the relay switch.

'7. In combination, a portable electric cable adapted for connection atone end to a portable electric tool, a support at the opposite end ofthe cable and. portable with the cable, a relay switch mounted on thesupport, the cable having electrical connection with one side of therelay switch, means independent of said electrical connection forsecuring the cable relative to the support, an element of an electriccontact means, which comprises quick-detachable cooperating elements,having electrical connection with the other side of the relay switch andbeing portable with the cable, a control circuit for the relay switch,and an electric switch for the control circuit, said switch being remotefrom the relay switch.

' MARION B. SAWYER.

